Having explained string theory to the masses in his bestseller The Elegant Universe and untangled the fabric of the cosmos in The Fabric of the Cosmos, the superstar physicist returns this month with The Hidden Reality, an ode to multiverse theory.

By now, the 11-dimension string theory models of his earlier books … are looking downright commonsensical. “The Hidden Reality” moves on to increasingly speculative and exotic discussions of a bubble multiverse (“Think of the universe as a gigantic block of Swiss cheese. …”) a holographic one, a brane-world scenario (courtesy of string theory), computer-driven simulations, questions of how probability relates to infinity, and the Many Worlds view of quantum mechanics. “A frequent criticism of the Many Worlds approach is that it’s just too baroque to be true,” Mr. Greene writes. [The New York Times]

Multiverse theory—the idea that our universe and its Big Bang were just one of many—is a favorite theme of science fiction (and “Family Guy”), as it allows us to have parallel selves in parallel universes. Greene explains the real science behind the idea with one of his litany of analogies: a simple deck of cards.

If you shuffle the deck infinitely many times, the card orderings must necessarily repeat. Similarly, in an infinite expanse of space, particle arrangements must repeat too—there just aren’t enough different particle configurations to go around. And if the particles in a given region of space the size of ours are arranged identically to how they are arranged here, then reality in that region will be identical to reality here. Except that maybe we’d be seeing the Jets and the Bears in the Super Bowl. [Wall Street Journal]

Once the basics of the multiverse are grounded in physics, Greene ponders a little philosophy. After all, not everyone is comfortable with the idea of infinite versions of themselves living out every conceivable path somewhere.

No flight of fancy, however wild, is denied existence. Every potential aspect of one’s character, suppressed in this universe, finds manifestation elsewhere. Bad fates in this universe are avoided in an infinity of others. And the multiverse settles all perplexing questions of “Why this?” with a simple, “Because we see only one thread of an infinite tapestry.” [Salon]

The Hidden Reality wins high marks with most reviewers, who praise Greene’s accessible treatment of an arcane cosmic subject. But not all. For some, like Scientific American‘s John Horgan, Greene’s taste “for the expansive” carries him too far out into the great abstract beyond.

My beef with Greene is this: He has become a cheerleader for the descent of theoretical physics into increasingly fantastical speculation, disconnected from the reality that we can access empirically. Greene has argued eloquently for the plausibility of string theory, which … postulates the existence of particles that are far too small to be detected in any conceivable experiment. [Scientific American]

Who was that famous guy, said something about imagination being more important than knowledge? IIRC, he did something that will be remembered longer than Mr. Who’s articles.

The multiple worlds theory makes just as much sense as the Copenhagen interpretation, especially when you get down to the fact that quantum mechanics can’t currently explain what it means by a ‘conscious observer’ in the role of collapsing quantum probability into our observed reality.

Everyone who’s said we’ve reached the end of knowledge has been shown a fool in the history books. There will be, there has to be a successor to general relativity and the standard model, because they can’t explain everything, or each other, but they both ‘work.’

Charles

Quote: “By now, the 11-dimension string theory models of his earlier books … are looking downright commonsensical.” Whoever wrote this for the NY Times should see the recent report from the Large Hadron Collider at CERN that experiments there have shown the 11-dimension version of string theory unlikely to be true. The quote is typical of these fantastical books and their fans. Just because the Standard Model and relativity are probably going to be superseded by another model of nature doesn’t mean that every hare-brained idea that comes along is true even if it works mathematically. There are any number of theories that work mathematically that have nothing to do with nature. String theory has a good number of challengers these days, including physicist Lee Smolin, who argues in his book “The Trouble with Physics” that it hasn’t produced an iota of proof in several decades and that it dominates the science like a mandate, freezing out any number of young scientists who want to work in alternative theoretical areas. The Big Bang has a lot of verifiable proof behind it. Please show me some proof for either string theory or the multiverse before you call any skeptic a closed-minded old fogey.

http://discovermagazine.com Andrew Moseman

@Charles
From the context of her piece, I believe the Times writer meant not that string theory is commonsensical to physicists, but rather in that simple in comparison to some of the far-out multiverse ideas Greene explores in the new book.

Dr Hoo

There are some incontrovertible bifurcations in simple physics that indicate something is, then isn’t, then is. Like the electron, for example, is an infinitely small point of no size that is either a wave or particle, but not all at the same time. Bifurcation, like when the electron tunnels right through solid matter is another example. We make every day use of these happenings. Television has to use these happenings to work at all. It would be a conveyance and possibly true to assume that it is possible to step out of this universe and then back again.

David George

Dr. Hoo writes,

“There are some incontrovertible bifurcations in simple physics that indicate something is, then isn’t, then is. Like the electron, for example, is an infinitely small point of no size that is either a wave or particle, but not all at the same time. Bifurcation, like when the electron tunnels right through solid matter is another example. We make every day use of these happenings. Television has to use these happenings to work at all. It would be a conveyance and possibly true to assume that it is possible to step out of this universe and then back again.”

So — an infinitely small point/wave/particle of no size and indeterminate status at any time tunnels through an arrangement of infinitely small point/wave/particles of no size and indeterminate status at any time, and television uses these happenings in order to work?

Are you certain (or even 95% probably certain, or 85%) of this?

Kamrava Pirouz

If this theory that we have existing replicates due to particles being arranged the exact same way is true, then there must be many, many, many other universes; which leads me to believe that the theory isn’t the best, although, of course, there is the slightest chance that it may be true.

cgauthier

…the descent of theoretical physics into increasingly fantastical speculation, disconnected from the reality that we can access empirically.

Is Horgan an idiot? How does an idiot maintain a post at Scientific American?

Physics is bored with “the reality that we can access empirically”. Things are happening that we cannot account for with empirical observation (yet), so we use theoretical physics to tease out the mathematical possibility of hypotheses for what these hidden aspects of reality are, so that we can eventually test them.

We may never actually be able to test some of them, due to technological shortcomings, but that alone does not invalidate the usefulness, or at least the rational satisfaction, of the speculation.

I mean, if the multi-verse hypothesis never leaves the realm of speculation, ever, it is still infinitely more plausible and philosophically satisfying than God or Karma or “this is the only possible universe and everything is the way it is because :-p”.

Prof. Enead

It is too bad that in such an advanced field of knowledge we would entertain speculation and pretend it’s anymore intelligent than the hokus pokus concept of a god personally involved in granting our individual wishes. Infinite Plausibility? Philosophical Satisfaction? These are still the concepts of a disturbed mind trying to validate irrationally some sense of lost satisfaction.

Stranger Strangeland

Generally new facts that clash with existing theory provide incentive to dream up new theoretical frameworks into which the new facts fit. What are the new facts that are supposed to be explained with string theory or multiverses? I enjoyed a science fiction novel titled Starman Jones when I was a kid. It was based on the idea that space is folded so that going from here to there is not lightyears if you can calculate where the shortcuts are and take them by reaching lightspeed. It was nifty speculation, and about as factually based as string theory, I’ve read.

http://totellyouthetruth-hi55.blogspot.com/ Holden is55 Caulfield

Mr Greene says, “…in an infinite expanse of space, particle arrangements must repeat too—there just aren’t enough different particle configurations to go around” and that’s where we get the multi- from in multiverse. That sounds a lot like, “I’ll betcha…”
I thought the multiverse idea was based on branching that occurs at (I suppose) all decision points, or something logical and theoretical-sounding like that.
Seems rather inelegant the way he says it.

David

Charles,

I am not familiar with the CERN findings you mention. Please cite them to defend the integrity of your comment.

Holden, branching is but one of many current ideas on the structure/creation of multiverses, I suggest more reading before making comments like yours.

Prof Enead, I have no idea what you are talking about, please gather your thoughts before making comments.

Dr. Hoo, you need to read more about particle physics, and then try to understand string theory. Your comment is misguided and off point.

You all seem to dismiss that math is driving a lot of the current theories, and math may be the only way we can test string theory. Or at least until we have the ability to “see” and analyze Planck dimensions (time, spatial and what ever else we discover along the way). Mr. Greene is trying to bring a theory that betrays all of our senses to a level of understanding for the rest of us. In doing this, I allow his analogies some latitude because how do you describe 10 spatial dimensions, 7 of which we have not seen yet? Keep open minds, I am not sure all of this can be dismissed as easy as someone not familiar with the concepts seem to be trying to do.

Holdenis55Caulfield

Pompous Dave:
…and what’s wrong with “comments like mine?”
If you really are the Galactic Public Relations point man for string theory, I think you need to be a lot less touchy. Try being business-like instead of emotions show; that’s professional.
As far as your recommended reading, I would start somewhere in the Emily Post area. That’s a historical reference; I apologize if I’ve overshot your cultural exposure.

Dr. Jinx

Oooooooo! I am not really a brainiac or a Dr. But I really love Brian’s books because he writes them in a way that I can comprehend these theories….I thoroughly enjoyed reading all your posts too….i love all the possibilities of physics and the universe and love to hear & read these discussions…rock on super brainiacs-without you the rest of us would be lost!!!